The present invention relates generally to liquid crystal displays, and more particularly, to a tool for use in affixing an optical component to a liquid crystal display.
Liquid crystal displays (LCDs) are well-known in the art and typically include a liquid crystal material that is sandwiched between a substrate and a filter, both the substrate and filter being traditionally constructed of glass.
In order to enhance or alter the performance of an LCD, additional optical components are often affixed to the substrate and/or filter of an LCD, the resultant product being commonly referred to as an LCD stack-up in the art. Examples of the types of additional optical components that are commonly affixed to an LCD to create an LCD stack-up include, but are not limited to, glass plates, diffusers, rigid compensators, heaters, and flexible films such as polarizers, retarders and dry film adhesives.
It is well known in the art for a transparent adhesive to be used to affix additional optical components to a liquid crystal display to create an LCD stack-up. For example, in U.S. Pat. No. 5,867,241 to J. D. Sampica et al. (hereinafter the '241 patent), which is incorporated herein by reference, there is disclosed an assembly fixture which is designed to assist in the application of a layer of silicone gel between a liquid crystal display and a first optical component. Once exposed to heat at a temperature of 80° C. for a period of 48 hours, the silicone gel cures which, in turn, serves to the attach the first optical component to the liquid crystal display with minimal strain imparted onto the liquid crystal display.
Although well known in the art, assembly fixtures of the type described in the '241 patent include a notable design shortcoming. Specifically, assembly fixtures of the type described in the '241 patent include no means for ensuring that the layer of silicone gel is deposited between the liquid crystal display and the additional optical component in a uniform manner. As can be appreciated, it has been found that the application of a non-uniform layer of silicone gel between the liquid crystal display and additional optical components ultimately compromises the performance of the resultant LCD stack-up, which is highly undesirable.
Accordingly, in U.S. Pat. No. 6,388,724 to M. L. Campbell et al. (hereinafter the '724 patent), which is incorporated herein by reference, there is disclosed a fixture for laminating an LCD to an additional optical component using silicone gel that includes a plurality of standoffs. In use, the plurality of standoffs serve to maintain adequate spacing between the LCD and the additional optical component to the extent necessary to ensure uniformity of the layer of silicone gel.